Fall in zone 5aPhoto: Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons
Frost dates for ZIP 81151 (Sanford, CO)
Average last spring and first fall frost dates with 10%, 50% and 90% odds, from NOAA's 1991–2020 climate normals for the nearest weather station, Manassa, CO (13 miles away).
- Average last spring frostMay 2850% chance of a 32°F freeze after this date
- Average first fall frostSep 2150% chance of a 32°F freeze by this date
- Growing season (frost-free)115 daysmedian, 32°F threshold
- USDA hardiness zone5a-20 to -15°F avg. coldest night
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This week in your yard
As of Oct 18, 2026, from your frost dates, zone and soil temperature. Lawn timing · Vegetables · Pruning · Plants
Soil temperature now
2-inch depth
No soil station with a fresh reading within 62 miles.
4-inch depth
No soil station with a fresh reading within 62 miles.
Fall: Texas A&M AgriLife times fall pre-emergent (for winter weeds such as annual bluegrass) to soil cooling to about 70°F for several days. The 50–55°F band is the spring trigger. Always read and follow the product label.
7-day forecast and frost risk
The latest National Weather Service 7-day forecast and any Frost Advisory or Freeze Warning for 81151 load here. You can also open the NWS forecast for this ZIP.
Pre-emergent
No soil reading near this ZIP. Typical extension timing for your region: spring mid-April to mid-May.
Fertilizer window
Lawn region: Mountain West and High Plains. Timing only; always follow the product label.
- Kentucky bluegrass (cool-season): Early fall: Around Labor Day (late August–September); Late fall: Late October–November, before the ground freezes; Late spring: Optional around Memorial Day. Avoid: Early-spring and midsummer feeding (pushes top growth, favors crabgrass).
Plant now
No vegetable planting windows are open this week.
Prune now
No frost-timed pruning windows are open this week.
Spring-flowering shrubs are pruned right after their flowers fade, not by date. See the pruning guide.
Last spring frost odds
| Chance of a 32°F freeze after this date | Date |
|---|---|
| 90% (early: most years still freeze after this) | May 13 |
| 50% (the "average" last frost) | May 28 |
| 10% (cautious: only 1 year in 10 freezes later) | Jun 11 |
Most gardeners plant frost-tender crops (tomatoes, peppers, basil) after the 50% date, and closer to the 10% date for less risk.
First fall frost odds
| Chance the first 32°F freeze has happened by this date | Date |
|---|---|
| 10% (early: 1 year in 10 freezes this soon) | Sep 9 |
| 50% (the "average" first frost) | Sep 21 |
| 90% (late: most years have frozen by now) | Oct 1 |
Light frost, freeze and hard freeze
| Threshold | Last spring (50%) | First fall (50%) |
|---|---|---|
| 36°F (light frost possible on clear, calm nights) | Jun 10 | Sep 11 |
| 32°F (freeze) | May 28 | Sep 21 |
| 28°F (hard freeze) | May 13 | Sep 29 |
n/a means NOAA did not publish a date at that threshold for this station (usually because it rarely gets that cold).
Vegetable planting calendar for 81151
Dates count from your average last spring frost (May 28) and first fall frost (Sep 21). Half of years have a frost after the spring date, so give tender crops (tomatoes, peppers, squash) some slack.
| Crop | Start indoors | Spring planting | Fall planting |
|---|---|---|---|
| Tomato | Apr 2–16 | Jun 4–18 (transplant) | – |
| Pepper (sweet and hot) | Mar 19–Apr 2 | Jun 11–25 (transplant) | – |
| Eggplant | Mar 19–Apr 2 | Jun 11–25 (transplant) | – |
| Tomatillo | Apr 2–16 | Jun 4–18 (transplant) | – |
| Lettuce | Apr 2–16 | May 7–28 (transplant) Apr 30–Jun 11 (sow outdoors) | Jul 27–Aug 17 (transplant) Jul 13–Aug 10 (sowing) |
| Spinach | – | Apr 16–May 7 (sow outdoors) | Jul 27–Aug 17 (sowing) |
| Kale | Apr 2–16 | Apr 30–May 14 (transplant) Apr 30–May 14 (sow outdoors) | Jun 29–Jul 27 (transplant) Jun 15–Jul 13 (sowing) |
| Collards | Apr 2–16 | Apr 30–May 28 (transplant) Apr 30–May 28 (sow outdoors) | Jun 29–Jul 27 (transplant) Jun 15–Jul 13 (sowing) |
| Broccoli | Mar 19–Apr 2 | Apr 30–May 14 (transplant) | Jun 15–Jul 13 (transplant) |
| Cabbage | Mar 19–Apr 2 | Apr 30–May 14 (transplant) | Jun 15–Jul 13 (transplant) |
| Cauliflower | Mar 19–Apr 2 | May 14–28 (transplant) | Jun 15–Jul 13 (transplant) |
| Brussels sprouts | Mar 5–19 | Apr 30–May 14 (transplant) | Jun 1–22 (transplant) |
| Kohlrabi | Apr 2–16 | Apr 30–May 14 (transplant) Apr 30–May 14 (sow outdoors) | Jul 13–27 (sowing) |
| Bok choy / Asian greens | – | Apr 30–May 14 (sow outdoors) | Jul 27–Aug 10 (sowing) |
| Arugula | – | Apr 30–May 28 (sow outdoors) | Jul 27–Aug 24 (sowing) |
| Mustard greens | – | Apr 30–May 21 (sow outdoors) | Jul 27–Aug 10 (sowing) |
| Swiss chard | Apr 16–30 | May 14–Jun 4 (transplant) May 14–Jun 11 (sow outdoors) | Jul 13–27 (sowing) |
| Beet | – | Apr 30–May 28 (sow outdoors) | Jul 13–27 (sowing) |
| Carrot | – | May 7–Jun 4 (sow outdoors) | Jun 29–Jul 13 (sowing) |
| Radish | – | Apr 23–Jun 4 (sow outdoors) | Aug 10–24 (sowing) |
| Turnip | – | Apr 30–May 21 (sow outdoors) | Jul 13–27 (sowing) |
| Parsnip | – | May 7–28 (sow outdoors) | – |
| Pea (garden, snap, snow) | – | Apr 2–30 (sow outdoors) | Jun 29–Jul 13 (sowing) |
| Onion (bulbing) | Mar 5–19 | Apr 16–30 (transplant) | – |
| Green onion / scallion | – | Apr 16–May 14 (sow outdoors) | Jul 13–27 (sowing) |
| Leek | Mar 5–19 | Apr 30–May 14 (transplant) | – |
| Garlic | – | – | Aug 10–Sep 7 (sowing) |
| Shallot | – | Apr 16–30 (transplant) | Aug 10–Sep 7 (sowing) |
| Potato | – | Apr 30–May 14 (transplant) | Jun 1–15 (transplant) |
| Sweet potato | – | Jun 18–Jul 2 (transplant) | – |
| Sweet corn | – | Jun 4–18 (sow outdoors) | – |
| Bean, bush (snap) | – | Jun 4–18 (sow outdoors) | – |
| Bean, pole | – | Jun 4–18 (sow outdoors) | – |
| Lima bean | – | Jun 11–25 (sow outdoors) | – |
| Southern pea (cowpea, black-eyed pea) | – | Jun 18–Jul 9 (sow outdoors) | – |
| Cucumber | Apr 30–May 7 | Jun 4–18 (transplant) Jun 4–18 (sow outdoors) | – |
| Summer squash / zucchini | Apr 30–May 7 | Jun 4–18 (transplant) Jun 4–18 (sow outdoors) | – |
| Winter squash | Apr 30–May 7 | Jun 4–18 (transplant) Jun 4–18 (sow outdoors) | – |
| Pumpkin | – | Jun 4–18 (sow outdoors) | – |
| Watermelon | Apr 30–May 7 | Jun 11–25 (transplant) Jun 11–25 (sow outdoors) | – |
| Cantaloupe / muskmelon | Apr 30–May 7 | Jun 11–25 (transplant) Jun 11–25 (sow outdoors) | – |
| Okra | Apr 16–30 | Jun 11–25 (transplant) Jun 11–25 (sow outdoors) | – |
| Celery | Mar 5–19 | Jun 4–11 (transplant) | – |
| Basil | Apr 16–30 | Jun 4–18 (transplant) Jun 4–18 (sow outdoors) | – |
| Cilantro | – | May 14–Jun 11 (sow outdoors) | Jul 27–Aug 10 (sowing) |
| Parsley | Mar 19–Apr 2 | May 14–28 (transplant) May 7–28 (sow outdoors) | – |
| Dill | – | May 28–Jun 11 (sow outdoors) | Jul 27–Aug 10 (sowing) |
| Sunflower | – | May 28–Jun 11 (sow outdoors) | – |
| Asparagus (crowns) | – | Apr 30–May 14 (transplant) | – |
| Rhubarb (crowns) | – | Apr 30–May 14 (transplant) | – |
| Strawberry (plants) | – | Apr 30–May 14 (transplant) | Jul 13–Aug 10 (transplant) |
Typical ranges from university extension planting calendars, adjusted to your frost dates. Probabilities, not guarantees. Fall windows that would overlap spring planting are left out, as are fall crops of frost-tender plants where the frost-free season is under 210 days.
Plants that do well here
Colorado has a university or garden plant program: Plant Select®. Plant frost-tender annuals after May 28 here (the average last frost). Not affiliated with the program.
Where these numbers come from
Station: Manassa, CO (NOAA GHCN-Daily ID USC00055322), elevation 7,695 ft, 13.4 miles from the ZIP's center point. NOAA completeness flag: R (representative, 10+ years).
Nearby stations
| Station | Distance | Last frost (50%) | First frost (50%) |
|---|---|---|---|
| Alamosa San Luis AP, CO | 16 mi | Jun 7 | Sep 15 |
| San Luis 1 S, CO | 16 mi | May 31 | Sep 23 |
| Alamosa 1E, CO | 18 mi | May 30 | Sep 17 |
The average last-frost dates of these stations span 10 days, a rough guide to local variation. See data sources & methods.
Frost questions for 81151
When is the last frost in 81151?
The average (50% chance) last spring freeze of 32°F for ZIP 81151 is May 28. For a more cautious planting date, use June 11, when only 1 year in 10 still sees a later freeze.
When is the first frost in 81151?
The average first fall freeze is September 21. In 1 year in 10 it comes by September 9.
What hardiness zone is 81151?
ZIP 81151 is in USDA zone 5a (-20 to -15°F average coldest winter night), per the 2023 USDA Plant Hardiness Zone Map ZIP listing.
What is the soil temperature in 81151 right now?
This page shows the latest 2-inch and 4-inch soil temperature from the nearest public soil station (USDA SCAN, NOAA USCRN or TexMesonet), or a labeled estimate when no station is close, against the 50–55°F spring pre-emergent band.
Nearby ZIP codes
81141 Manassa 81123 Blanca 81138 81148 Romeo 81101 Alamosa 81152 San Luis 81129 Conejos 81126
Other ZIP codes in Costilla County
81123 81126 81133 81138 81152 All Costilla County frost dates · Colorado frost dates
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- Freeze alerts
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Free. One weekly email plus alerts when your ZIP has a frost or a soil-temperature change worth acting on. After you submit, Kit (our email provider) sends a confirmation email: check your email and click the link to confirm. You aren't subscribed until you do. We collect only your email address and ZIP, sent to Kit to deliver The Dial. Unsubscribe anytime.